The bathroom is, when you think about it, a vile place: Since flushing the toilet launches aerosolized toilet funk into the air, virtually everything you touch could be coated with a fine mist of invisible poo particles. For that reason, washing your hands after peeing is an absolute must.
But don’t stop there, because drying your hands properly is equally as important when it comes to reducing the number of germs on your mitts (because it can re-apply the germs that were just washed off, which we’ll touch on momentarily). But between paper towels, warm-air dryers and jet-air dryers (the toaster-like ones you stick your hands right into, instead of waving them about below), which is least likely to give you a fresh coat of bacteria? Let’s find out.
According to a 2016 study published in the Journal of Applied Microbiology, jet-air dryers spread 60 times more germs than standard warm-air dryers, and 1,300 times more germs than paper towels (the researchers also note that most of this bacteria spews directly at the height of a child’s face). Prior to that, a 2014 study found equally unnerving results: Airborne germ counts were 27 times higher surrounding jet-air dryers in comparison with the air around paper towel dispensers.
It’s worth noting, however, that the researchers who conducted the 2016 study piled unrealistic amounts of the MS2 virus—a bacteria-inhabiting virus that’s harmless to humans, but useful for experimentation purposes—onto the gloved hands of the participants (the researchers were working under the assumption that many of the germs being spread by these dryers come from the under-washed hands of their users). “The amount of virus is enormous, huge, gargantuan—a massive, massive load,” Jon Otter, a British epidemiologist and the interim head of operations for Infection, Prevention and Control for Imperial Hospital, told Slate.
The subjects also didn’t actually wash their hands—they simulated washing by shaking their gloved hands before dunking them into the jet-air dryer, which (hopefully) doesn’t reflect actual bathroom behavior, but let’s be honest, people are gross. Anyway, for these reasons, the study is regarded as being pretty unrealistic.
Even more recently (and disturbingly), a microbiology professor found a large mass of fungal growth in a petri dish after placing it in an enclosed air-jet dryer for just three minutes. Alarming photos of the mass garnered 500,000 shares on Facebook in a matter of days—naturally, the manufacturer of the hand dryer responded, saying in a statement to ABC that they were, “Very surprised to see these results, and unclear on the methodology employed.”
But despite some evidence that these experiments may have been conducted under artificial conditions, a 2012 Mayo Clinic review concludes that paper towels still reign supreme: “From a hygiene viewpoint, paper towels are superior to electric air dryers. Paper towels should be recommended in locations where hygiene is paramount, such as hospitals and clinics.”
That’s partially because most of us simply don’t have the patience to fully dry our hands with a warm-air or jet-air dryer, and moist hands collect more bacteria. “Most people dry their hands for a bit, then wipe them on their dirty jeans, or open the door with their still-wet hands,” Rodney Lee Thompson, a hospital epidemiologist at the Mayo Clinic, told the Wall Street Journal.
So it looks like we have a winner, in the form of those ever-reliable paper towels. But at the end of the day, this entire argument is somewhat moot, because it’s virtually impossible to do anything at all without coating yourself in a fresh layer of germs. Which means you can either be the kind of person who touches every communal object with a tissue, or you can just live your life and hope for the best.
Plus, unless you have a medical reason to avoid everyday germs, air dryers are better for the environment. So there’s that.